Last year, 750,000 Americans traveled abroad for care, according to estimates by the Deloitte Center for Health Solutions, a Washington-based research center. Other analysts say the numbers are lower, but hardly anyone disputes that medical care, once a highly local business, is going global like never before. By 2010, Deloitte projects, 6 million consumers a year will venture outside the United States for medical treatment. Proponents say it's a logical outgrowth of the globalization that's reshaping the industry.